全球供应链时代的货币政策

MONETARY POLICY IN AN ERA OF GLOBAL SUPPLY CHAINS

作者：

魏尚进

谢银溪

We study the implications of global supply chains for the design of monetary policy, using asmall-open economy New Keynesian model with multiple stages of production. Within thefamily of simple monetary policy rules with commitment, a rule that targets separate producerprice inflation at different production stages, in addition to output gap and real exchange rate, isfound to deliver a higher welfare level than alternative policy rules. As an economy becomesmore open, measured by the export share, the optimal weight on the upstream inflation risesrelative to that on the final stage inflation. If we have to choose among aggregate price indicators,targeting PPI inflation yields a smaller welfare loss than targeting CPI inflation alone. As theproduction chain becomes longer, the optimal weight on PPI inflation in the policy rule thattargets both PPI and CPI inflation will also rise. A trade cost shock such as a rise in the importtariff can alter the optimal weights on different inflation variables.
我们使用具有多个生产阶段的小开放经济新凯恩斯模型研究了全球供应链对货币政策设计的影响。在带有承诺的简单货币政策规则系列中，除产出缺口和实际汇率外，针对不同生产阶段的单独生产者价格通胀的规则被发现比替代性政策规则具有更高的福利水平。随着经济的开放（以出口份额衡量），上游通胀的最优权重相对于最后阶段的最优权重增加。如果我们必须在总价格指标中进行选择，那么与仅针对CPI通胀相比，针对PPI通胀所产生的福利损失要小。随着生产链变长，同时针对PPI和CPI通胀的政策规则中对PPI通胀的最佳权重也会增加。诸如进口关税上升之类的贸易成本冲击会改变不同通货膨胀变量的最佳权重。